<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0"> 
  <title>Document</title>
  <style>
    .wrapper{font-size:36px;color:#f90;}
  </style>
</head>
<body>
  <div class="wrapper">
     about页面内容
  </div> 
  <button id="test">click</button>
</body>
</html>